Renewable resilient guard for insertable vibratory tools



DeC- 27, 1949 A. J. KROECKEL. 2,492,43

RENEWABLE RESILIENT GUARD FOR INSERTABIJE VIBRATORY TOOLS Filed Aug. 27,1948 FIG. I.

l I5 I6 24 23 25 I4 2O I9 2\2 26 2l 28 27 3l 29 304 INVENTOR LFIIEI) J.IIROECIIEL ATTORNEY Patented Dec. 27, 1949 RENEWABLE RESILIENT GUARD FonINSERTABLE vIBRA'roRY TooLs Alfred Kroeckel, Viber Company,

Burbank, Calif., assigner to a corporation of California applicati@August 27, 194s, serial No; 46,455

2 Claims.

This invention relates to;a renewable resilient guard for insertableVibratory tools.

One object of the invention is to provide a resilient guard or nose onan insertable tubular vibrator used particularly in compacting unsetconcrete. Another object is to provide a wearresisting nose for aninsertable tubular vibrator such as those used for compacting concrete.A further object is to provide an insertable tubular vibrator having arenewable, wear-resisting resilient nose.

These and other objects are attained by my invention which will beunderstood from the following description and the accompanying drawingsin which:

Figure 1 is a side elevational view of one form of insertable tubularvibrator mechanism having a resilient nose;

Figure 2 is a cross-sectional view taken on the line 2-2 of Figure 1;and

Figure 3 is a perspective view of a renewable resilient guard fortubular vibrators.

Tubular insertable vibrators for use in compacting unset concrete havenow become standard tools in the construction industry. Because of thesevere mechanical abuse and wear to which such tools are subjected, ithas heretofore been considered necessary to use the hardest and tougheststeel cases and noses on the insertable portions of the vibrators. Ihave discovered that surface wear resistance of a vibrator may begreatly increased by the use of a guard made of resilient material, suchas soft vulcanized rubber, preferably vulcanized in position on the nosepiece only of the vibratory tool.

In the preferred form of my invention shown in the drawings, a highspeed electric motor II having a control switch I2 and a handle means I3is connected mechanically to an eccentric weight encased vibratormechanism indicated generally as I4, by means of a flexible drive shaftI5 within a flexible casing I6 which is attached to the motor housing I1by the coupling I8, the flexible drive shaft I 5 being suitablyconnected to the shaft of the motor. The flexible casing I6 and theexible drive shaft I5 may be of any desired length, in practicefrequently being fifteen to twenty feet long especially when thevibrator is used for compacting concrete placed between high forms suchas in walls for buildings. The vibrator I4 consists of a short rigidshaft I9 mounted in ball bearings 2li and 2l which are supported in thecylindrical metal casing 22. The inner end of the shaft I9 is extendedby the spline connector 23 which is adapted to removably reattached tothe outer shaft I5, the spline .connection being enclosed within anextension 25 of the cylindrical casing 22. An eccentric weight 26 ismounted on or made integral with the shaft I9 in the space between thebearings. The outer end of the casing 22 is closed by the plug member 21which is preferably welded at 28 to the periphery of the casing tosecure it mechanically as well as to prevent any leakage of water fromthe outside. The plug member 21 is provided with a threaded stud 29extending axially from its end, which engages the nose piece 30. Thenose piece 3U consists of a metal body member having a diameter at thebase 2I equal to the diameter of the casing 22 and also of the plug 21,and is provided with a terminal metal knob 32 with an undercutcircumferential groove 33 at the base of the knob. The resilientcovering 34 preferably made of soft vulcanized rubber known generally astire tread stock is arranged to fit over the knob 32 with an insideflange portion 35 fitting into the groove 33, the outer face of theresilient guard being substantially hemispherical in shape. The shapedresilient guard 34 is preferably vulcanized on the `knob 3'2 of the nosepiece 30 so that there is strong adhesion between the inside surfaces ofthe resilient guard 34 and the outside knob 32 and groove 33. The rubbercovered nose piece may be used on other forms of insertable tubularvibrators. When the resilient rubber guard has become worn, it isreplaced by removing the nose piece 30 from the screw threaded stud 29and a new nose piece, having a new resilient guard vulcanized on itsmetal knob 32 is attached to the stud '29.

The advantages of my invention will be apparent from the abovedescription. Vibrators of this general type are commonly operated at10,00()l R. P. M. and in use are embedded in gravel, sand and rock,sometimes under considerable pressure. The resilient rubber guard noseattached to the end of a tubular vibrator has been found to have anegligible damping effect upon the action of the vibrator, in contrastto the unsuccessful use of rubber as a protective cover over the entireinsertable portion of the vibrator. In addition to the increasing oflife for the nose piece of a vibrator, the resilient guard hasyeliminated the destruction of wood forms in which the unset concrete isvibrated in the making of walls, which occurs when a vibrator endinadvertently comes in contact with the form itself. It will beunderstood that in normal practice, the vibrator is embedded andsurrounded by concrete, but particularly when used in forms forrelatively narrow walls, the end of the vibrator frequently is pressedinto contact with the side walls of the Wood forms. When the nose pieceis made of non-resilient material such as steel, the wood forms arerapidly cut, abraded and roughened so that they cannot be re-use.VPlywood is 'frequentlyused in building such forms and because of itshigh costrmust, in order to be practicable, be re-used in making forms.The use of vibratory tools having my resilient nose pieces hasgreatlyncreasedfthe life of plywood forms and thereby decreased the,cost of preparing vibrated concrete walls.

I claim:

1. In a vibratory tool having avibratory mechanism encased in a rigidmetal `tubular .rhousi'ng and adapted to be inserted in granularmaterial to be compacted, a knob-shaped metal nose piece at the end ofsaid housing, and a resilient vulcanized :rubber :coating VVdi?substantial thickness vulcanized securely vin place nver'the :entiresur- )face .o'f :the maior zporltion .of fthe outside of .said :metal`nose piece.

ALFRED J. KROECKEL.

REFERENCES CITED The .ollowlng .references are of record in the le ofVthis patent:

UNITED STATES PATENTS Number Name Date 1,989,409 Gordon Jan.,29, 1935$236,392 Barry-etal. Mar. 25, 1941 2,278,839 'Douglass Apr. 7, 1942

